COL4A3 and chronic kidney disease: In a systematic review of 777 patients with heterozygous COL4A3/COL4A4 mutations in 258 families, 28.6% of whom received kidney biopsy; microhematuria with/without macrohematuria, proteinuria (>0.5 g/day), CKD, and ESKD were observed in 89.1%, 41.6%, 29%, and 15.1%, respectively [2].